In recent years, portable phones which have been widely disseminated go multifunctional and provide various services. A portable phone with a music regeneration function which can store MP3 music information and the like downloaded from a music distribution site and reproduce the music any time you want has been developed lately.
However, in this type of portable phones, a speaker embedded in the portable phone or head phones or earphones connected through a cable to an earphone terminal have to be used when listening the music. Therefore, there are problems that the reproduced music is poor in sound quality and that a cumbersome work is required to listen the music.
Taking these problems into consideration, portable phones or adaptors having a configuration for performing frequency modulation (FM) to the reproduced music information to transmit without wires have been suggested (for example, see Patent Documents 1, 2, and 3). Patent Document 1: Japanese Patent Application Laid-open No. H6-309854; Patent Document 2: Japanese Patent Application Laid-open No. 2003-110665; Patent Document 3: Japanese Patent Application Laid-open No. 2003-204375.
In an adaptor described in the above Patent Document 1, using a CD player secured to the adaptor body together with an FM transmitter provided to the adaptor body, a sound signal outputted from the CD player is converted to an electronic wave in an FM band to be transmitted without wires to a radio with an existing FM. Then, the sound of the CD player can be outputted from an acoustic system inside a car by tuning the radio.
In a portable phone described in the above Patent Document 2, music data stored in a storage part is read out and reproduced as a music signal through decoding and the like. The reproduced music signal is subjected to frequency modulation to be transmitted as an FM signal through an FM antenna. By receiving the FM signal with an FM radio and reproducing the FM signal through demodulation in the FM radio, the music reproduced in the portable phone can be outputted with volume reinforced to the desired level.
A portable phone described in the above Patent Document 3 comprises a key input part for key inputting, a music information storage part for storing music information, music regeneration part for reproducing the music information as a music signal, FM part for performing FM to the music information, and main controlling part for controlling the whole portable phone. Detecting the ON position in the key input part, the main controlling part performs FM to the reproduced music signal in the FM modulation part to transmit without wires.